Radiator Pressure Cap Assembly for Nissan Cooling System

This small but critical cooling component seals the radiator/filler neck and keeps the system under the correct pressure. Proper pressure raises the coolant boiling point, helping your engine stay stable in traffic, hot weather, and long highway runs.

Why this part is needed ✅

Your engine makes heavy heat. This cap assembly controls pressure and allows coolant to move safely to the overflow tank and back again. Without the right seal and spring force, cooling efficiency drops fast.

How it works ⚙️

Inside are a calibrated spring and valves. When pressure rises above spec, it vents coolant to the reservoir. As the engine cools, vacuum opens the return valve and pulls coolant back, keeping the radiator full and preventing air pockets.

What happens if it’s broken

• Coolant loss, sweet smell, wet neck area
• Overheating or boiling over after shutdown
• Collapsed hoses from bad vacuum control
• Heater turns weak due to trapped air
• Risk of head gasket damage from repeated overheating

Compatibility

• Altima
• Maxima
• Teana
• Murano
• Elgrand
• Quest